Question: what is the binary star has the highest color index?
Paraphrase: The highest color index belongs to which binary star?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q50053 . ?ent wdt:P1458 ?obj } ORDER BY DESC(?obj)LIMIT 5 
Answer: Proxima Centauri, Beta Apodis, Eta Serpentis, Eta Carinae, Altair